Azimuthally-distributed wavy inner wall treatment for high subsonic jet noise control  

作　　者：Zhenyu NIU Shang WANG Xiaoquan YANG Xiaolong TANG Peifeng WENG 

机构地区：[1]Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China [2]School of Mechanics and Engineering Science,Shanghai University,Shanghai 200072,China [3]Shanghai University of Electric Power,Shanghai 200090,China

出　　处：《Chinese Journal of Aeronautics》2025年第3期413-434,共22页中国航空学报(英文版)

基　　金：support from the National Natural Science Foundation of China(Nos.12372256,12072186).

摘　　要：The noise generated by subsonic jet nozzles, commonly encountered in civilian aircraft, is rather significant and propagates in both the upstream and downstream directions due to large-scale and fine-scale turbulence structures. In this paper, a distinctive inner wall treatment strategy, denoted as the Azimuthally-distributed Wavy Inner Wall (AWIW), is proposed, which is aimed at mitigating jet noise. Within this strategy, a circumferentially dispersed treatment wall characterized by a minute wavy pattern is substituted for the smooth inner wall in proximity to the nozzle outlet. To assess the effectiveness of the AWIW treatment, we conducted numerical simulations. The unsteady flow field and far-field noise were predicted by employing Large Eddy Simulations (LES) coupled with the Ffowcs Williams and Hawkings (FW-H) integration method. To gain a comprehensive understanding of the mechanism underlying the noise reduction facilitated by the AWIW treatment, it examined physical parameters such as the Lighthill source acoustic source term, the turbulent kinetic energy acoustic source term, and the shear layer instability. The results reveal that the AWIW treatment expedites the instability within the shear layer of the jet, leading to an early disruption of the jet shear layer, and consequently turbulent structures in varying sizes are generated downstream. This process effectively regulates the generation and emission of jet noise. By controlling the minor scale turbulence through the AWIW treatment, the mid- and high-frequency noise within the distant field can be significantly reduced. In the context of the flow field, the introduction of AWIW also leads to a decrease in drag on the inner wall surface of the jet, thereby improving the overall aerodynamic performance of the nozzle. Considering these attributes, the AWIW strategy emerges as a viable technique for the reduction of jet noise.

关 键 词：Jet noise Azimuthally-dis tributed wavy inner wall Jet noise control Large eddy simulation Drag reduction 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]